Q. 13.15 - An Introduction to General, Organic, and Biological Chemistry

Question

Indicate whether each pair of Fisher projections represents enantiomers or identical structures.

Step-by-Step Solution

Answer

Part a. The given structure is identical.

Part b. The given structure is an enantiomer.

Part c. The given structure is an enantiomer. 

Part d. The given structure is an enantiomer. 

Step 1:Introduction (Part a)

• Fischer devised a simplified method for depicting the atom configurations around the chiral carbons. 
• Vertical lines in this three-dimensional structure represent bonds that extend backward from a carbon atom, while horizontal lines represent bonds that extend forward.
• The intersections of horizontal and vertical lines depict chiral carbon atoms.

Step 2: Explanation(Part a)

• Enantiomers are chiral compounds that are not superimposable and are mirror reflections of one another. 
• Stereoisomer compositions with molecules that are not mirrored images of one another and are not superimposable are known as diastereomers. 
• They are mirror images of each other that cannot be superimposed.

Step 3: Determine the given structure is an enantiomer or identical structure(Part a)

When two atoms are identical and may be superimposed, the mirror image shows the same structure.

Step 4: Explanation(Part b)

• Enantiomers are chiral compounds that are not superimposable and are mirror reflections of one another. 
• Stereoisomer compositions with molecules that are not mirrored images of one another and are not superimposable are known as diastereomers. 
• They are mirror images of each other that cannot be superimposed.

Step 5: Determine the given structure is an enantiomer or identical structure(Part b)

When both structures are non-superimposable mirror images of each other, they are enantiomers.

Step 6: Explanation(Part c)

• Enantiomers are chiral compounds that are not superimposable and are mirror reflections of one another. 
• Stereoisomer compositions with molecules that are not mirrored images of one another and are not superimposable are known as diastereomers. 
• They are mirror images of each other that cannot be superimposed.

Step 7: Determine the given structure is an enantiomer or identical structure(Part c)

When both structures are non-superimposable mirror images of each other, they are enantiomers.

Step 8: Explanation(Part d)

• Enantiomers are chiral compounds that are not superimposable and are mirror reflections of one another. 
• Stereoisomer compositions with molecules that are not mirrored images of one another and are not superimposable are known as diastereomers. 
• They are mirror images of each other that cannot be superimposed.

Step 9: Determine the given structure is an enantiomer or identical structure(Part d)

When both structures are non-superimposable mirror images of each other, they are enantiomers.